Rotary Cutter Rotary cutter maintenance ... pure newbie questions

[ArmsOutWide]

I have a new Rhino 172 rotary cutter. I bought it with the tractor and it came already attached to the 3pt / pto. I'm a complete tractor newbie and I haven't even learned how to remove/attach it yet (the dealer did install a quick hitch for me, so I hear that it will help tremendously).

I'm going to typically use it ~ 1-2 hours at a time, working about 8-10 hours total over a couple of weeks to mow my property. I'll probably repeat that scenario 4-5 times per year (so ~30-50 hours / year total mowing).

I have a lot of oak saplings (1"-1 1/2") to knock down the first time through, and I have tons of rocks, although they are relatively soft (sandstone). I do know that the cutter has a slip clutch, although I'd be hard pressed to tell you what one looks like at this point.

So, I've been reading my manual, and a bunch of old posts, and I'm just as confused as when I started. I think I have a list of questions though.

Given my usage patterns, how often should I (in days / weeks / months / tractor hours / cutter hours / whatever unit is best):
1) Check / replace the gearbox oil
2) Check / replace the blades
3) Do that re-adjust the slip clutch thing that sounds so complicated (I've already scalped a couple rocks, and got a puff of smoke out of the clutch ... at least I think that's what happened ... which sounds like a good thing based on what I've read so far)
4) Perform any other maintenance checks / adjustments that I'm not experienced enough to know to mention

Can I be certain that the dealer attached the thing correctly the first time? I've taken it out for ~ 1 1/2 hours and it SEEMS to be fine (grass knocked down, trees chewed up, rock collisions survived, etc). However, the deck doesn't seem to raise up until I hit a 6 out of 8 on the 3pt position control lever. Someone mentioned in another thread that I probably needed to adjust the top link, so I'll try that out as soon as I get the chance. It also goes down really fast (and hits pretty hard). Is that just a gravity thing?

Finally, the manual also talks about checking driveline lengths and hights and cutting stuff to fit, etc. Are those common tasks / problems?

Thanks in advance for the education. Hopefully I'll be a fast learner.

 

[Farmwithjunk]

I have a new Rhino 172 rotary cutter. I bought it with the tractor and it came already attached to the 3pt / pto. I'm a complete tractor newbie and I haven't even learned how to remove/attach it yet (the dealer did install a quick hitch for me, so I hear that it will help tremendously).

I'm going to typically use it ~ 1-2 hours at a time, working about 8-10 hours total over a couple of weeks to mow my property. I'll probably repeat that scenario 4-5 times per year (so ~30-50 hours / year total mowing).

I have a lot of oak saplings (1"-1 1/2") to knock down the first time through, and I have tons of rocks, although they are relatively soft (sandstone). I do know that the cutter has a slip clutch, although I'd be hard pressed to tell you what one looks like at this point.

So, I've been reading my manual, and a bunch of old posts, and I'm just as confused as when I started. I think I have a list of questions though.

Given my usage patterns, how often should I (in days / weeks / months / tractor hours / cutter hours / whatever unit is best):
1) Check / replace the gearbox oil
2) Check / replace the blades
3) Do that re-adjust the slip clutch thing that sounds so complicated (I've already scalped a couple rocks, and got a puff of smoke out of the clutch ... at least I think that's what happened ... which sounds like a good thing based on what I've read so far)
4) Perform any other maintenance checks / adjustments that I'm not experienced enough to know to mention

Can I be certain that the dealer attached the thing correctly the first time? I've taken it out for ~ 1 1/2 hours and it SEEMS to be fine (grass knocked down, trees chewed up, rock collisions survived, etc). However, the deck doesn't seem to raise up until I hit a 6 out of 8 on the 3pt position control lever. Someone mentioned in another thread that I probably needed to adjust the top link, so I'll try that out as soon as I get the chance. It also goes down really fast (and hits pretty hard). Is that just a gravity thing?

Finally, the manual also talks about checking driveline lengths and hights and cutting stuff to fit, etc. Are those common tasks / problems?

Thanks in advance for the education. Hopefully I'll be a fast learner.

Everyone has their opinions, and I'm sure there'll be a few that are contradictory to mine, but here goes.

On the gearbox oil. I don't normally change oil but once a year. (winter) I'd CHECK it frequently, maybe every other time you use it. More frequently if you suspect leaking. If you see any signs of contamination, then adjust the changing schedule to suit that. Mower gearboxes SOMETIMES will collect condensation and/or rain water through the vent.

Blades. I inspect them (visual) every day they're used. They get sharpened as needed. (done in place with an angle grinder) In all my years, I've replaced ONE pair of blades after getting into a pile of old re-bar buried in the weeds. That bent both blades. I have spare blades on hand for all of my mowers but haven't ever needed to change them. Bush Hog type blades don't need to be in "perfect" condition, and you absolutely DON'T want them "sharp", especially if you're cutting saplings and such. Sharp blades make clean, sharp cuts on the saplings, leaving you with a field full of tire killers. Slightly blunt edges on the blades shatter the saplings, saving your tires.

If you're seeing the slip clutch "slip", it doesn't need much at this time. It's best to service it at the beginning of the season, then periodically throughout the year. A great deal depends on how (where) you store the mower. Exposed to the elements, the slip clutch can start to rust. At that point, it's subject to siezing.

From time to time, again, usually at the start of each days use, do a "walk-around" and inspect for loose bolts, broken welds, missing parts, ect. In MOST conditions, you'll not find much of anything wrong. But sure enough, DON'T LOOK, and you'll ALWAYS miss these problems until it's too late.

Some tractors have a response control on the hydraulics. That will control speed of lift AND drop (in most cases) Not knowing what tractor you're using, I can't say for certain.

HOPEFULLY...If the dealer sent you the tractor and mower hitched and ready to mow, he's already checked PTO shaft length. (But don't assume anything) They normally come from the manufacturer at a length that will allow them to work on just about any tractor. In some instances, the shaft will be too long. (Rare, but possible that it's too short) It's a simple matter of cutting equal amounts off of each half of the shaft to get enough, but not too much overlap. A.S.A.E. (American Society of Agricultural Engineers) has a standard measurement of pto stub to drawbar end and pto stub to 3-point hitch ball-ends. Unfortunately, not all manufacturers of compact tractors, or implement manufacturers subscribe to that standard. I'd suggest starting with a simple questioning of your dealer as to the pto shaft length being correct.

By the way, I own and operate a mowing business. This past summer, we logged nearly 2800 hours (spread across 4 tractors) of bush hogging with a variety of mowers. It's not rocket science. A properly set up and serviced tractor/mower can run many hours with little or no problems, especially with a CAREFUL, ALERT operator.

 

[RobJ]

Can't add much, The gear oil can go a lot longer. How often do you change the rear end oil in your car/truck. Most probably never and that sees a lot more action. But we tend to be kinder to our toys. And just make sure everyting is tight.

Let her rip!

 

[Texas Dodge]

I always check the gear oil and grease the rear wheel everytime I use mine

 

[mjfox6]

I grease the tire and tire shaft grease ports every 10 hours when I grease everything else. I grease the PTO shaft every time I take the mower off, more often would be nice.

The knob under your seat adjusts the rate at which your 3pt descends. Just turn it until you get it to fall at a rate you are happy with.

The slip clutch isn't very difficult to adjust. There are step by step instructions on TBN somewhere. Here is what the slip clutch looks like:

 

[Soundguy]

Ditto on the recs posted here. I also change my gear oil 1xper year as FWJ does... and check the box avery couple uses.

Check that slip clutch at least 1x per year before you use it.. if not more often.. especially if you get months of inactivity between uses and it sets outside.

Keep the wheel bearing and spindle bearing greased. Sharpen the blade as needed but keep in mind a brush blad only needs about a 1/16 flat edge.. not a razor sharp blade like a lawnmower... sharpendinghte blade will make it wear faster and suffer more damage from rocks.. etc.

Soundguy

 

[daBear]

Having just blown the seals out of a gear box, at least make sure the gear box is covered with a tarp from the rain. If it fills up through the vent hole you can blow the seals and it's about $60 to have them replaced. If you pull the box and just take that in.

 

[RalphVa]

Given my usage patterns, how often should I (in days / weeks / months / tractor hours / cutter hours / whatever unit is best):
1) Check / replace the gearbox oil -- I check mine periodically. Actually, I think it's like on your car/truck transmission/differential. Only check when or if you see some leakage. I'd only replace if you see some oil slinging from the bottom seal or maybe at around 10 years. This has been my method on my cars and pickup. Changed it on my Gravely, and it stopped the wheel seal leakage.
Guess one has to use a suction gun to remove the oil from the gear case? Haven't changed mine yet, as it's only 3 years old.
2) Check / replace the blades -- If mine seems out of balance, I check them. Usually, swinging them to and fro and restarting fixes any imbalance. I remove the blades once/year and sharpen them on a bench grinder. Only put maybe 50 hours on it/yr. Use a 6' piece of pipe to loosen and retighten them.
3) Do that re-adjust the slip clutch thing that sounds so complicated (I've already scalped a couple rocks, and got a puff of smoke out of the clutch ... at least I think that's what happened ... which sounds like a good thing based on what I've read so far) -- don't have on the LX4. Had one on the Gravely. Never touched it. It seemed to work when needed.
4) Perform any other maintenance checks / adjustments that I'm not experienced enough to know to mention -- check for any lost pins every time you use it. Make sure the PTO is locked in place if removed and put back on. Tug it in and out. Disengage the PTO or put in "front" position (disengages if you have front & rear ones). Then you can rotate the shaft by hand when holding the cutter shaft head up to it. When you feel it go in, THEN depress the collar or button to loosen the locking gizmo. Shove on, release collar or button and tug to and fro. Always grease with white lithium first.

Make yourself a dolly for the front of the unit to sit on if you can store it on a concrete floor. Then you can roll it away to storage and roll it back to mount it. All you need is a 1by with add'l 1by on ends to which you attach some castors. Just don't forget to remove the dolly once it's mounted!

Adjusting the level is tricky until you figure it out. Park on level, paved area. Basically set your rear wheel to have cutting height about 1/2" to 1" above front. Level front with adjustable side of 3ph arm. Lower to desired height. There may be an adjustable gizmo on your cutter to center. On my LX4, it has a slide gizmo that you adjust the top link to center it. Make sure your top link is same length to shorter than bottom lift arms. If top link is longer, raising lift arms will drive the tail wheel into the ground. On my LX4, it came with the bottom pins in the wrong location such that the top link had to be too long. Wouldn't lift. Dumb dealer rep!

Ralph

 

[randot]

I can speak from experience, be sure to grease the wheels with plenty of grease when you do. I just had to replace all four wheels on my rhino finish mower. I greased them on the ten hour schedule, but did not put more then one pump of the grease gun in each wheel. You can see the wear marks on the axle bolt in the pic. On that same note, is there an advantage to using pneumatic tires over the solid tires? I have very level ground without anything obvious to cause flats and my thought is the pneumatics would stay inline better than the solid rubber tires and create less divots on the grass.